The sidewalks were frozen, and pedestrians conveying themselves to the Metro, the store or the sled hill had little choice. Dance they must. The art of it lay in which of the three prevailing modes they chose to express themselves. There was the comedic, the tragic and the technical.

The comedians walked stiffly, as if their clothes were soaking wet, or they were trying for laughs in a silent movie. To keep their balance, they were prone to sudden, jerky movements and exaggerated facial expressions, like French mimes depicting something completely unrecognizable.

The tragedians walked slowly, woefully, heads down, limbs drawn into their torsos. To maintain their footing, they purged all personality, individuality and gender from their gait. No flouncing, strutting, bopping. Theirs was a depression shuffle, as if they had just left the funeral of their last friend.

The technicians pretended this was nothing. They took meticulous steps, prudently planting heel and toe simultaneously. They studied terrain, evaluated ice composition and varied ambulatory strategy accordingly. They knew when to walk in the plowed street, when to seek the surer footing of the sugared grass, when to tough it out on the sidewalk bobsled run.

"You can't be in a hurry," said Alvin Jenkins, a technician, walking home from the market in Brookland. He used his grocery bag of fish and broccoli for extra balance.

"Walk very softly," said Paul Edmonds Sr., another technician, who soft-footed it to the Minnesota Avenue NE Metro station.

"You're going to fall!" said Sacha Langer, stepping gingerly along an encrusted sidewalk in Silver Spring.

"No, I'm not!" replied Willa Schneiderhan, who was skating in her boots.

The girls are young yet, high school sophomores, not settled on a particular ice dancing style. But they have advice: "You have to stomp," said Schneiderhan, who demonstrates a hard blow with her boot to get purchase on the softening surface of the ice.

That method wouldn't have worked earlier in the morning, when the ice was hard and jeweled. But everyone had advice.

"You've got to keep your center of gravity low to the ground," said James Scheurer, a contractor from Clinton.

Three men leaving a shop in Brookland linked arms and successfully scaled the hill to the intersection of 12th and Monroe Streets NE. But the curb cut for wheelchairs foiled them. They started sliding sideways into the intersection. One let go of his cigarette and grabbed a newspaper box, like a swimmer reaching for the edge of a dock before being carried out to sea.

The change in grade comes as a shock. Slowly, inexorably, you drift in a different direction, like a golf ball breaking on a putting green.

Tim McGarry was doing what looked like an impression of Wile E. Coyote running in thin air. The Catholic University freshman's legs scrambled on the ice, and he was laughing and talking to himself. Tim, what were you thinking?

"I was thinking about how I gotta tell my friends in San Diego about this!" he said. Then he skated like an otter down a curb cut. All comedy.

Kenny Ames looked unfazed in his black pinstripe suit, descending a slick hill to the Brookland Metro station. He's from Boston, a technician with comic touches. The aplomb on his face was punctuated with jerky spasms of his body, as if puppet strings were yanking up his arms in random salutes to the world.

"I almost fell," he admitted. But he caught himself with a balance-saving lunge, which he demonstrated again: "You ever see anybody dancing and they reach back like that?"

It takes years to learn a move like that. Ice dancing is all about instinct and reflex, disciplined by experience.

The morning was a chance to take children to discover ice. They clung to their parents, amazed at the bewitched properties of this cold, strange solid. A toddler would lose her footing, and the parent would reach in for the heroic arm-dangling save.

"It's been a lot of fun watching Caden figure out ice," said Jill Clark, who was pushing her 2-year-old son in a stroller. The stroller, not incidentally, kept her from falling more than once.

Caden reminded her of the rules she taught him about ice. The first rule: "We don't run on ice!"